galactic evolution – Astronomy Now

Tracking a star’s movement by measuring its age and chemistry

16 September 2018 Astronomy Now

By measuring a star’s age and chemical makeup, astronomers can determine where a sun originated in the galactic disk before migrating outward. The Sun, it turns out, likely formed about 2,000 light years closer to the Milky Way’s core.

Fierce molecular winds slow runaway starbirth in early galaxy

6 September 2018 Astronomy Now

Astronomers have detected a powerful molecular wind being blasted away from a starburst galaxy in the early universe, the earliest example yet of a mechanism thought to prevent galaxies from growing too large too fast.

Supercomputer simulation reverse engineers star cluster formation

27 June 2018 Astronomy Now

Supercomputer simulations show star clusters, regardless of size, form in the same way, starting with a dense cloud of interstellar gas and shaped over several million years by gravity, turbulence and radiation pressure

Supermassive black holes squelch star formation in ancient galaxies

23 June 2018 Astronomy Now

Observations by NASA’s Chandra X-ray Observatory of two five-billion-solar-mass black holes at the cores of two ancient ‘red nugget’ galaxies show they squelched star formation early on while consuming surrounding gas.

Edge-on view highlights galaxy’s dust lanes, hides spiral structure

18 May 2018 Astronomy Now

As seen from Earth, galaxies can appear in any number of orientations, from face on, with spiral arms on glorious display, to edge on, with the arms hidden from view behind a flattened plane of stars and dust. While not as spectacular, perhaps, edge-on views provide key insights into galactic structure.

Star formation underway 250 million years after Big Bang

17 May 2018 Astronomy Now

Astronomers using ESO’s Very Large Telescope and the Atacama Large Millimetre/submillimetre Array have observed a galaxy 13.3 billion light years away that includes stars that must have been shining just 250 million years after the Big Bang.

Ancient ‘red and dead’ galaxy sheds light on big bang relics

12 March 2018 William Harwood

Astronomers have identified a relatively nearby “relic galaxy,” a massive collection of ancient stars that may shed light on galaxy formation in the ancient universe.

A ringside seat for a slow-motion galactic train wreck

8 March 2018 William Harwood

The Hubble Space Telescope captures a snapshot of a collision between two galaxies 350 million light years away in the constellation Cetus, giving astronomers a ringside seat to a slow-motion merger that eventually will result in a single combined galaxy. Gravitational interactions are distorting the barred spirals, ripping away stars and dust.

Modest-mass galaxy hosts oversized black hole: an evolutionary missing link?

24 September 2015 Astronomy Now

The central supermassive black hole of a recently discovered galaxy called SAGE0536AGN is far larger than should be possible, according to current theories of galactic evolution. The galaxy was found by accident with NASA’s Spitzer space telescope and is thought to be at least 9 billion years old. Time will tell whether SAGE0536AGN really is an oddball, or simply the first in a new class of galaxies.